Add pulsing outline to hollow example.

examples/hollow.rs

@@ -20,13 +20,18 @@ fn main() {
         .add_systems(Startup, setup)
         .add_systems(
             Update,
-            (setup_scene_once_loaded, rotates, rotates_hue, close_on_esc),
+            (
+                setup_scene_once_loaded,
+                rotates_and_pulses,
+                rotates_hue,
+                close_on_esc,
+            ),
         )
         .run();
 }
 
 #[derive(Component)]
-struct Rotates;
+struct RotatesAndPulses;
 
 #[derive(Component)]
 struct RotatesHue;
@@ -55,11 +60,11 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
             scene: asset_server.load("hollow.glb#Scene0"),
             ..default()
         })
-        .insert(Rotates)
+        .insert(RotatesAndPulses)
         .insert(OutlineBundle {
             outline: OutlineVolume {
                 visible: true,
-                width: 7.5,
+                width: 0.0,
                 colour: Color::BLUE,
             },
             stencil: OutlineStencil {
@@ -97,11 +102,17 @@ fn setup_scene_once_loaded(
     }
 }
 
-fn rotates(mut query: Query<&mut Transform, With<Rotates>>, timer: Res<Time>, mut t: Local<f32>) {
+fn rotates_and_pulses(
+    mut query: Query<(&mut Transform, &mut OutlineVolume), With<RotatesAndPulses>>,
+    timer: Res<Time>,
+    mut t: Local<f32>,
+) {
     *t = (*t + timer.delta_seconds()) % TAU;
     let a = t.sin();
-    for mut transform in query.iter_mut() {
+    let b = 10.0 * (3.0 * *t).cos().abs();
+    for (mut transform, mut volume) in query.iter_mut() {
         *transform = Transform::from_rotation(Quat::from_rotation_y(a));
+        volume.width = b;
     }
 }